Memristor Behaviour in Nano-Sized Vertical Lsmo/Lsmo Tunnel Junctions

TL;DR

This paper demonstrates memristor behavior in nano-sized LSMO tunnel junctions, driven by an electronic polaronic mechanism involving electric-field-controlled Jahn-Teller effects and orbital reconstruction.

Contribution

It reveals a novel electronic memristance mechanism in LSMO films, distinct from ionic memristors, with unique high-field switching behavior.

Findings

Memristor behavior with nonlinear I-V characteristics observed in LSMO films.

Switching occurs at a bias field of approximately 1 MV/cm.

Additional high-field LRS-HRS switching due to Jahn-Teller energy minima.

Abstract

We report a memory resistance (memristor) behavior with nonlinear current-voltage characteristics and bipolar hysteretic resistance switching in the nanocolumnar manganite (LSMO) films. The switching from a high (HRS) to a low (LRS) resistance occurs at a bias field ~1 MV/cm. Applied electric field drops mostly at the insulating interfacial LSMO layer and couples to correlated polarons at the LSMO(111)/LSMO(111) vertical interfaces. The observed memristance behaviour has an electronic (polaronic) origin and is caused by an electric-field-controlled Jahn-Teller (JT) effect, followed by the orbital reconstruction and formation of a metastable orbitally disordered interfacial phase (LRS). Compared to the earlier reported ionic memristor in Ti-O films, an electronic (polaronic) nano-sized LSMO memristor shows an additional (re-entrant) LRS-HRS switching at higher fields because of the second minimum in the elastic energy of a JT system.